'The indie version of a princess': Beth Ditto photographed by Eamonn Mccabe. Photograph: Eamonn Mccabe for the Guardian

It's only page 10 of Beth Ditto's slim but gripping memoir and we're already eating squirrels. Three luckless rodents are shot by Ditto's stoned cousin Dean, who skins them, guts them, fries them up and devours them in a fit of the munchies. He leaves the clearing-up to Ditto, who has just had her first suck on a bong made out of a Coke can.

All this was normal in Ditto's native semi-rural Arkansas in the early 90s. "My dad liked to boil a squirrel head and suck the brains out the nose," Ditto expands. "Smaller than a chicken, bigger than a rat. I hadn't eaten squirrel since I was a kid," she confides, "and it would take more than stoner munchies to get me to snack on it again."

Anyone au fait with the rise of Beth Ditto and her gay-positive punk band, Gossip (formerly the Gossip), will recall that formative squirrel-eating was, in the early years, a big part of Ditto's extraordinary USP. After six years underground, Gossip tore up 2006 with a dancefloor anthem, Standing in the Way of Control, which started out as a protest against the Bush government's stance on gay marriage and quickly became the soundtrack for Channel 4 teen drama Skins, before becoming inescapable.

In the process, Ditto – soul-voiced, plus-sized, outspoken, glam – went from being the charismatic front-woman of a cult band to being feted as a mainstream icon; the indie version of becoming a princess. Her deprived Arkansas childhood was a significant part of the coal-to-diamonds myth: times were hard, protein was protein.

In her new life, though, she partied with Kate Moss; appeared naked on magazine covers, in a glorious effort to counteract body fascism; and even became an agony aunt for the Guardian, a role that suited her down to the ground.

Ditto had been trying to solve the problems of her ailing aunt Jannie, her troubled mother, and her vulnerable younger siblings and cousins before her move, after high school, to the more simpatico climes of the Pacific north west. There, thanks to the vibrant punk subculture – one rife with feminist leanings – that spawned Kurt Cobain, gay alterna-misfits could not only feel at home: they were almost 10 a penny.

The squirrels are just the half of it, though. A year ago, some of the bait trailing this autobiography was the promise of graphic sexual revelations – or at least, those were the quotes that got reported. Nonetheless, Ditto hinted at passages about going down on girls; stuff that would make squirrels blanch.

Actually, Ditto's adult sex life is dealt with primly, when at all. The prurient should know there's no cunnilingus here, and move along. Other omissions are more puzzling. We end the book thinking Ditto's still going out with her long-time transgendered partner, Freddie, when in fact she is engaged to marry her former assistant Kristin Ogata next year. A sterner co-writer (she had help from San Francisco poet Michelle Tea) or a firmer editor might have helped with the confusing leaps about in time, too.

No, the shocks lie elsewhere. "I started begging Anthony to knock me up," writes Ditto, of her high-school boyfriend (she hadn't quite come out yet). As much as Ditto felt a misfit in Judsonia, Arkansas – Christian, poor, isolated – there was a part of her that craved babies, and would have preferred not to burn in hell. Anthony, to his credit, refused; possibly the one instance in which any man in this book acquits himself with anything like decency. The other exception is Nathan Howdeshell (also known as Brace Paine), Gossip's guitarist, and Ditto's buddy since high school, one of a crowd of slightly older misfits who instructed Ditto in what little counterculture Judsonia allowed in.

A different book review might reveal the full horror of Ditto's ferociously dysfunctional childhood, and its repercussions. Suffice to say, it makes The Jeremy Kyle Show look like Waybuloo. But the right to tell that story is Ditto's, and is included in the book price.

Of all the music autobiographies published this autumn, this one is, probably, the lightest on music. There's little exegesis of Gossip's many excellent albums, only one of which is famous. But you don't miss it, because Ditto's own trials and tribulations – told largely in her own voice – are so riveting. And it is surely the only rock memoir to use the word "hornswoggled" – another good reason to just get past the squirrel thing, and appreciate the real meat here.